A gas turbine engine typically includes a fan section, a compressor section, a combustor section, and a turbine section. A fan section may drive air along a bypass flowpath while a compressor section may drive air along a core flowpath. In general, during operation, air is pressurized in the compressor section and is mixed with fuel and burned in the combustor section to generate hot combustion gases. The hot combustion gases flow through the turbine section, which extracts energy from the hot combustion gases to power the compressor section and other gas turbine engine loads. The compressor section typically includes low pressure and high pressure compressors, and the turbine section includes low pressure and high pressure turbines.
Various sections of a gas turbine include channels, compartments, or plenums through which air and/or combustion gases flow. For example, a blade outer air seal (BOAS), which is disposed radially outward from a blade/airfoil array, is generally designed to have a specific fluid pressure on a radially outward surface of the BOAS in order to maintain a desired cooling effect and, to a lesser extent, to maintain a desired radial clearance between tips of the rotating blades and a radially inward surface of the BOAS. The pressure of the air on the radially outward surface of the BOAS is conventionally controlled and supplied via an orifice in an upstream support wall of a gas turbine engine.